N = int(input())
S = input()
from collections import Counter
d = Counter(list(S))
allr = d["R"]
leftd = Counter(list(S[:allr]))
leftr = leftd["R"]
print(allr-leftr) N = int(input()) N int(input()) int input() input S = input() S input() input from collections import Counter d = Counter(list(S)) d Counter(list(S)) Counter list(S) list S allr = d["R"] allr d["R"] d "R" leftd = Counter(list(S[:allr])) leftd Counter(list(S[:allr])) Counter list(S[:allr]) list S[:allr] S :allr allr leftr = leftd["R"] leftr leftd["R"] leftd "R" print(allr-leftr) print allr-leftr allr leftr S = input() input() S leftr = leftd["R"] leftd["R"] leftr d = Counter(list(S)) Counter(list(S)) d N = int(input()) int(input()) N allr = d["R"] d["R"] allr leftd = Counter(list(S[:allr])) Counter(list(S[:allr])) leftd
N = int(input())
S = input()
from collections import Counter
d = Counter(list(S))
allr = d["R"]
leftd = Counter(list(S[:allr]))
leftr = leftd["R"]
print(allr-leftr)